Power supplies are used in every electronic device. There are several types of DC to DC power supplies including switching regulators and low drop-out regulator (LDO) used in different applications. A switching regulator uses an active device that switches on and off to maintain an average value of output.
A Pulse Width Modulation (PWM) mode switching power regulator uses a PWM clock to switch one or more switches to regulate input voltage to provide a constant output voltage.